In the manufacture and maintenance of electronic assemblies as well as other electrical apparatus the need frequently arises to remove a quantity of solder as for example to disconnect an electrical component from a printed circuit board. While various techniques have been employed in the past to remove such solder, one accepted method that is in widespread use involves the capillary action of metallic braid to draw molten solder from a work-piece. Forms of such desoldering braid and its uses are disclosed in U.S. Pat. Nos. 3,627,191 and 3,715,797. A desoldering braid having a loose flattened tubular configuration is described in co-pending application of Jesse C. Hood, Ser. No. 457,837 filed Jan. 14, 1983. A process for producing desoldering braid of such loose configuration is described in co-pending application of Jesse C. Hood, Ser. No. 457,838, now abandoned filed Jan. 14, 1983.
There are several advantages attendant upon the use of desoldering braid. For example, the technique of using the braid, as in conjunction with a soldering iron, is somewhat related to the activity of soldering and is, therefore, familiar to technicians in the field. Furthermore, removing solder by the use of desoldering braid is relatively fast and effective and the removed solder is captured and held in the braid. Consequently, loose particles of solder are not left about an electrical apparatus.
To use the desoldering braid, a section of braid is first placed over the unwanted solder. The braid so positioned is contacted with a soldering iron to heat the braid and melt the solder. Capillary action of the desoldering braid then draws the molten solder in the braid removing it from the undesired location.
Desoldering braid is generally furnished wound around a spool or bobbin. One form of bobbin acceptable for this purpose is described in U.S. Pat. No. 3,430,886, the disclosure of which is hereby incorporated by reference.
Bobbins provide support for desoldering braid and permit quick and easy winding of the braid thereon and removal of the braid therefrom.
For best results, a bobbin for desoldering braid should be small in size and compact to permit carriage in a tool box or similar receptacle or on the person such as in a pocket. It should permit the manufacturer to easily wind the braid thereon and the user to readily remove the braid for use in desoldering. Heretofore, bobbins for desoldering braid such as the bobbin disclosed in U.S. Pat. No. 3,430,886, mentioned above, have not provided any means for securing the end of the desoldering braid to the bobbin during winding of the braid onto the bobbin. The loose end of the braid tends to slip as the bobbin is wound with the braid until the end is caught by the braid being wound upon it. Thus, commencing the winding of the braid upon the bobbin is somewhat cumbersome and does not result in uniformly wound bobbins.
In addition, it has been observed that as the braid is pulled from the bobbin, friction between the desoldering braid, which is metallic or at least has a metallic outer surface, and the bobbin, which is generally fabricated from a plastic material, can produce electrostatic discharges, which may be destructive of sensitive electronic equipment upon which the desoldering braid is being used.
Accordingly, it is an object of the present invention to provide a bobbin for desoldering braid which has none of the previously mentioned disadvantages.
Another object of this invention is to provide a bobbin construction which will prevent the end of the braid from slipping during winding of the braid upon the bobbin.
Another object of the invention is to eliminate friction between the desoldering braid and the bobbin when the braid is pulled from the bobbin.
Another object of the present invention is to provide a bobbin in which friction between the desoldering braid and the bobbin does not result in the production of electrostatic discharges.
Other objects, advantages and capabilities of the invention will become apparent from the following description taken in conjunction with the accompanying drawings in which like parts bear similar reference numerals.
The bobbin of the present invention includes a body having a hub portion for holding and supporting a winding of desoldering braid, first head having a substantially flat portion extending outwardly from one end of the hub portion and a second head having a curling portion of a flexible material extending outwardly from the other end of the hub portion and establishing a surface portion overlying and in close tolerance with the peripheral edge of the flat head portion, so as to enclose a winding of the braid on the hub portion when curled inwardly to a first position, and extending outwardly from the hub portion in substantially spaced relation to the first head portion when curled outwardly to a second position, to prevent winding of the braid on the hub portion. The hub portion contains a slot wider than the braid for receiving an end of the braid and adapted to be narrowed by applying pressure to the ends of the hub portion to hold securely an end of the braid and to narrow the distance between the heads during winding of the braid upon the compressed hub portion and to be widened and to cause the distance between the heads to be widened to their normal widths upon ceasing the application of pressure to the ends of the hub portion. The end of the braid is thereby released from the slot and the braid is supported loosely upon the hub portion between the heads. The bobbin may be fabricated of a conductive plastic material to prevent static electrical discharges.